On June 1, 1921, he began serving in the Highest Evaluating Commission[clarification needed] with the 34th Infantry Regiment in Biała Podlaska.

During his studies and service with the General Staff, he officially remained officer of the 21st Infantry Regiment "Dzieci Warszawy" ("Warsaw's Children").

[2] He was a confidant of Józef Beck, the foreign minister, who considered Chodacki the best politician among the officers transferred from military service to diplomacy.

[15] During Chodacki's service as Commissioner, the work of Polish Intelligence was intensified and employees of the Commissariat collected information about the military preparations in Gdańsk.

As the result of protests by the previously-expelled Carl Jacob Burckhardt, High Commissioner of the League of Nations in Gdańsk, the Germans released Chodacki and others over the Lithuanian border on September 5.

[1] On March 11, 2019, by decision number 491 of the Polish Minister of National Defense, Marian Chodacki was posthumously promoted to the rank of lieutenant colonel.